title: Validity and responsiveness of radiographic joint space width metric measurement in hip osteoarthritis: a systematic review.
abstract: OBJECTIVE
  To perform a systematic review of the literature on the concurrent validity, predictive validity and responsiveness of radiographic metric measurement of femoro-acetabular joint space width (JSW) in hip osteoarthritis (OA).
  
  
  METHODS
  
  
  
  METHODS
  studies reporting any data on (1) JSW on X-rays in hip OA patients and (2) concurrent validity (correlations with clinical symptoms), predictive validity (correlations with future symptomatic state, joint space loss or joint replacement), and/or responsiveness (JSW change over time evaluated using the standardized response mean (SRM)).
  
  
  METHODS
  Medline PUBMED and Embase databases.
  
  
  METHODS
  Random-effects models were constructed to obtain pooled SRMs.
  
  
  RESULTS
  Of 448 articles, 79 met the abstract inclusion criteria and were read for further screening. Of these, 15 reported measures of validity and 11 reported measures of responsiveness. Concurrent validity: Five studies suggested an association between JSW and symptoms in the general population. Two evaluated the correlations between JSW and symptoms in hip OA patients, with conflicting results. Five demonstrated that JSW is predictive of future hip joint replacement. Responsiveness was moderate (SRM=0.66; 95% confidential interval (95%CI): 0.41, 0.91), but tended to be lower in randomized clinical trials than in cohort studies (0.35 vs 0.83), using an intention to treat rather than a completer analysis (0.30 vs 0.80), and using manual rather than computer-based measurement (0.47 vs 1.12).
  
  
  CONCLUSIONS
  There is evidence of a weak association between JSW and symptoms, of predictive validity for subsequent joint replacement, and of moderate responsiveness of metric measurement of JSW.
authors.affiliation: Department of Rheumatology, Tours University Hospital, Tours, France.
authors.forename: D
authors.initials: D
authors.lastname: Chu Miow Lin
authors.forename: W M
authors.initials: WM
authors.lastname: Reichmann
authors.forename: L
authors.initials: L
authors.lastname: Gossec
authors.forename: E
authors.initials: E
authors.lastname: Losina
authors.forename: P G
authors.initials: PG
authors.lastname: Conaghan
authors.forename: J F
authors.initials: JF
authors.lastname: Maillefert
mesh_terms: D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D018450:Disease Progression; D005260:Female; D006621:Hip Joint / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D011379:Prognosis; D011859:Radiography; D015203:Reproducibility of Results; D016896:Treatment Outcome